Electrical connecting apparatus

ABSTRACT

An electrically connecting apparatus comprises a base member provided with slots penetrating in the plate thickness direction, contacts disposed within the slots so as to be able to contact electrodes of a device under test on the base member and for connecting the electrodes to an electric circuit of a tester, and an elastic member. The contacts has a fixed piece to be fixedly held on the base member within the slots for connection with the electric circuit, and a movable piece disposed within the slots for electrical connection with the fixed piece. In the fixed piece, a guide face for guiding the movable piece toward a contact position permitting the movable piece and the electrodes to contact is formed, and the movable piece is supported slidably on the guide face so as to receive elastic biasing force toward the contact position by the elastic member.

TECHNICAL FIELD

The present invention relates to an electrical connecting apparatussuitable for use as auxiliary means in an electric test of asemiconductor device such as an integrated circuit.

BACKGROUND ART

In a test of electric characteristics of an integrated circuit (IC)sealed by a package, a mold and the like, is generally used auxiliarymeans for testing comprising an electrical connecting apparatus calledsocket. Each electrode of a semiconductor device as a device under testis movably connected to an electric circuit of a testing apparatus suchas a tester through this electrical connecting apparatus. This type ofelectrical connecting apparatus is described in Patent Document 1.

Patent Document 1: Japanese Patent Appln. Public Disclosure No. 8-233900Official Gazette

The electrical connecting apparatus described in Patent Document 1comprises a plate-like electrically insulating housing with a pluralityof slots penetrating in a plate thickness direction, and a device undertest (DUT) board, on which a circuit to be connected to a tester isformed, is attached to the underside of the housing. Also, on the upsideof the housing, a semiconductor device to be tested is disposed so thata lead as its electrode may extend toward each slot. Each contact ismade of a conductive contact base member and a conductive contactmember. The contact, disposed in each slot, is slidable on a guide faceof the contact base member. Each contact base member is elasticallysupported within the slot of the housing so as to be pressed toward thecircuit on the board provided on the underside of the housing by theelastic biasing force of two elastic members traversing each slot. Also,both the elastic members exert their elastic biasing force to eachconductive contact member. Each conductive contact member is disposedwithin the housing slidably on the guide face of the correspondingcontact base member and is disposed in the housing with its contact endportion projected from the upside of the housing.

Consequently, by pressing the lead of the semiconductor device againstthe conductive contact member of each corresponding contact, each leadis connected to the corresponding circuit on the board through thecontact base member on which the conductive contact member slides, whichenables testing by the tester.

In the heretofore electrical connecting apparatus, however, theconductive contact base member and the conductive contact member guidedto slide by the conductive contact base member are elastically supportedon the housing by the above-mentioned two elastic members. For thisreason, when the lead of the semiconductor device is pressed against theconductive contact member for a test, a contact end of the conductivecontact member to the lead slides on the lead with the sliding of theconductive contact member. At this time, the conductive contact basemember slidably receiving the conductive contact member on the guideface also slides slightly on the circuit of the board.

When the contact end of the conductive contact member slides on thelead, the lead surface is sometimes slightly scraped. However, this isonly once at the time of testing and does not cause the lead to have anygreat damage or abrasion. Moreover, since the oxide film on the leadsurface is removed by the sliding, electrical connection between thelead and the contact end of the conductive contact member is ensured, sothat this sliding is desirable.

On the other hand, when the conductive contact base member slides on thecircuit of the board, the circuit portion is subjected to slightabrasion. However, the board, different from the electrode of thesemiconductor device to be tested, is subjected to repeated sliding ofthe conductive contact base member every time a new semiconductor deviceis tested. Consequently, the conductive contact base member and thecircuit portion of the board on which the conductive contact base memberslides are prone to be worn, thereby causing to spoil durability.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

It is, therefore, an object of the present invention to provide anelectrical connecting apparatus excellent in durability in comparisonwith a conventional one.

Means to Solve Problems

The present invention relates to an electrical connecting apparatus forconnecting the electrode of a device under test to an electric circuitof a tester, and comprises: an electrically insulating plate-like basemember for receiving the device under test having slots penetrating inits plate thickness direction; contacts disposed within the slots so asto contact the electrode of the device under test on the base member andfor connecting the electrode to the electric circuit of the tester; andan elastic member. The contact has a fixed piece to be fixedly heldwithin the slots on the base member for connection to the electriccircuit; and a movable piece disposed within the slots and electricallyconnected to the fixed piece. In the fixed piece, a guide face forguiding the movable piece to a contact position to permit contactbetween the movable piece and the electrode is formed. The movable pieceis supported by the elastic member to slide on the guide face so as toreceive elastic biasing force toward the contact position.

It is possible to fix a wiring base plate on one face of the base memberand to receive the device under test on the other face side of the basemember. A wiring portion which is connected to the electric circuit ofthe tester and with which the fixed piece is brought into contact isformed on the wiring base plate, and the fixed piece is electricallyconnected to the electric circuit through the wiring portion.

The movable piece may have a projected portion which can project fromwithin the slot over the other face of the base member.

The fixed piece can be engaged with a peripheral wall of the slot of thebase member by an engaging mechanism.

The engaging mechanism can be constituted by a projection formed on theperipheral wall of the slot and a recess formed in the fixed piece forengagement with the projection.

The guide face can be formed angularly with respect to the center linepenetrating openings of both ends of the slot. When the movable pieceslides along the guide face, an amount of displacement of a Z-axialdirection component along the center line can be greater than the amountof displacement of the movable piece along an X-axial direction which isthe longitudinal direction of the slot as viewed by a planar shape ofthe slot orthogonal to the center line.

The guide face can be a straight guide face extending angularly withrespect to the center line of the slot.

The fixed piece may have: a bottom portion disposed along one of thefaces of the base member within the slot and along the longitudinaldirection of the slot; a first upright portion closer to the other faceof the base member from one corner portion of the bottom portionlongitudinally of the slot; and a second upright portion raised alongthe first upright portion at an interval from the other side of thebottom portion and terminates at a lower height position than that ofthe first upright portion. In this case, the guide face is formed on theface of the first upright portion confronting the second uprightportion. The movable piece receives the elastic biasing force of theelastic member between both the upright portions so as to abut the guideface.

In correspondence to the array of electrodes of a device under test, aplurality of the slots can be formed in alignment in their widthdirections. In each slot, contacts each including the movable piece andthe fixed piece are disposed in alignment, and a single elastic memberis disposed across the aligned slots in the width direction of the slotsso as to exert the elastic biasing force to each movable piece withinthe aligned plural slots.

The contact can be a Kelvin connector contact made of a laminatedstructure provided with a pair of conductive layers and an electricallyinsulating layer between the conductive layers.

EFFECT OF THE INVENTION

In the electrical connecting apparatus according to the presentinvention, since the fixed piece for slidably guiding the movable pieceof the contact is fixedly held on the base member within the slot, thefixed piece does not slide with the sliding of the movable piece everytime the movable piece slides, thereby preventing lowering of durabilitydue to abrasion accompanying the sliding of the fixed piece.

Also, the fixed piece being fixedly held on the base member, if a wiringbase plate in contact with the wiring portion of this wiring base plateis provided in the base member, the fixed piece contacting the wiringportion of the wiring base plate is prevented from sliding at everyinspection on the wiring portion, thereby surely preventing the fixedpiece and the wiring portion from wearing by sliding and therebyimproving the durability.

By forming the projected portion in the movable piece, the front end ofthe projected portion projecting from the inside of the slot at thecontacting position can be surely brought into contact with theelectrode.

By employing an engaging mechanism in combining the fixed piece and thebase member, the fixed piece can be surely and easily coupled with thebase member fixedly.

By forming the above-mentioned engaging mechanism with the projection inthe peripheral wall of the slot and the recess in the fixed piece, it ispossible to insert the fixed piece into the slot so as to avoid theprojection and to engage the recess of the fixed piece with theprojection of the slot at a position where the recess of the fixed piececorresponds to the projection of the slot wall, thereby combining bothof them more surely and easily, and realizing more efficient assemblingwork.

By making the amount of displacement of the X-axial component of themovable piece greater than the amount of displacement of the X-axialcomponent, the moving distance of the movable piece sliding on theelectrode face of the device under test can be set smaller when theelectrode of the device under test is pressed against the movable pieceof the corresponding contact. Since this can prevent the contact fromdeviating from the electrode due to a great displacement of the movablepiece, this favorable for an electrical test of a miniaturizedsemiconductive device provided with a smaller sized electrode.

By making the guide face a straight guide face as mentioned, a favorableguide face can be easily and accurately formed without causing any greaterror.

Compact contacts with a relatively simple structure and an electricalconnecting apparatus having the contacts are realizable, by providingfirst and second upright portions apart from each other and rising fromthe bottom portion of the fixed piece, by forming a guide face of themovable piece relative to the first upright portion and by disposing theelastic member relative to both upright portions.

Also, elastic biasing force appropriate for action of a plurality ofcontacts can be applied so that a favorable electrical connection can beobtained by the elastic biasing force of a single elastic member, bydisposing a single elastic member traversing a row of the slots at eachslot row. Thus, there is no need to provide two elastic bodies asheretofore in each slot row, thereby simplifying the constitution.

Also, by employing a Kelvin connector contact made of a laminatedstructure as a contact, influence by contact resistance of the contactis reduced, so that it becomes possible to measure even a device undertest having a low resistance value at a high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of the electrical connecting apparatusaccording to the present invention.

FIG. 2 is a plan view showing a base member with a cover of theelectrical connecting apparatus in FIG. 1 removed.

FIG. 3 is a partially enlarged bottom view of the base member showing arow of slots provided therein shown in FIG. 2.

FIG. 4 is a section with a cross section in FIG. 1 partially enlarged.

FIG. 5 is a perspective view showing the contact in FIG. 4 in anexploded state.

FIG. 6 is a view similar to FIG. 4 showing the electrical connectingapparatus in a testing state.

FIG. 7 is a perspective view showing a Kelvin connector contact in anexploded state.

FIG. 8 is a perspective view of the Kelvin connector contact.

EXPLANATION OF REFERENCE NUMERALS

-   10 electrical connecting apparatus-   12 base member-   14, 114 contact-   14 a, 114 a fixed piece-   14 b, 114 b movable piece-   16 elastic member-   20 device under test (semiconductor IC)-   20 a electrode (lead)-   22 slot-   28 a, 128 a bottom portion of fixed piece-   28 b, 128 b first upright portion of fixed piece-   28 c, 128 c second upright portion of fixed piece-   32 b, 132 b guide face (straight inclined guide face)-   36, 136 recess of engaging mechanism-   38 projection of engaging mechanism-   46, 146 projection of movable piece-   48 wiring base plate-   48 a wiring portion of wiring base plate-   50 tester

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1 representing a vertical section, the electricalconnecting apparatus 10 according to the present invention comprises: abase member 12; a plurality of contacts 14 called probes to beincorporated into the base member; at least one rod-like elastic member16 having a circular cross sectional shape for applying elastic biasingforce to the plural contacts 14; and a plate-like cover member 18 to beremovably attached to the base member 12 through bolts (not shown). Theelastic members 12 can be made of a synthetic rubber such as silicon gumor urethane rubber.

FIG. 2 is a top view of the base member 12 with the cover member 18removed. As shown in FIG. 2, the base member 12 is made of a plate-likenon-conductive material and has a rectangular planar shape. In thecentral area of the base member 12, a plurality of slots 22corresponding to respective electrodes of a semiconductor IC 20 which isthe device under test shown in FIG. 1, namely, leads 20 a are aligned.Each slot 22 is formed to penetrate from the bottom face 12 a of thebase member 12 through the upper face 12 b.

In the example shown in FIG. 2, screw holes 24 for receiving the boltsfor fixing the cover member 18 on the base member are formed at each ofthe four corners of the base member 12. Also, in the example shown inFIG. 2, paired two slots 22 are disposed with the central portion of thebase member 12 in-between and at an interval in the horizontal (X)direction, and each pair of the slots 22 are disposed so as to alignwith each other in the vertical (Y) direction. As is clear from FIG. 3which shows the planar shape of the slots 22 in an enlarged state, eachslot 22 has a rectangular planar shape with the horizontal (X) directionas the longitudinal direction and each corner portion is rounded. Thecontacts 14 are disposed in respective slots 22, and in order to giveelastic biasing force to the contacts 14, the elastic member 16 isdisposed along the width direction (Y-axial direction) of the slots 22so as to traverse the row of the slots 22 aligned mutually in thevertical (Y) direction.

Referring to FIG. 1 again, a rectangular opening portion 18 a forreceiving a semiconductor IC 20 is formed in a cover 18. The rectangularopening portion 18 a is formed to penetrate the cover member 18 in thethickness direction and to permit the upper end of each slot to beexposed partially on the upper face 12 a of the base member 12. In theillustration, in order to enable smooth insertion of the semiconductorIC 20 into the rectangular opening portion 18 a, each peripheral wallsurface portion 26 of the opening portion is constituted by an inclinedplane so that the rectangular opening portion 18 a may expand upward.

As shown in FIGS. 4 and 5, the contact 14 disposed in each slot 22 has afixed piece 14 a and the movable piece 14 b to be slidably held on thefixed piece. Each of the pieces 14 a and 14 b can be made of a metalsuch as a nickel alloy, tungsten or beryllium, or a precious metal suchas palladium.

As shown in FIG. 4, the fixed piece 14 a has a bottom portion 28 aextending in the longitudinal (X-axial) direction of the slot 22 byconforming the underside to the bottom face 12 a of the base member 12within the slot 22; a first upright portion 28 b rising from the bottomportion along one corner portion of the slot 22 toward the upper face 12b of the base member 12; and a second upright portion 28 c rising fromthe bottom portion 28 a along the other corner portion of the slot 22 atan interval from the first upright portion 28 b along the first uprightportion.

As shown in FIG. 1, in the pairing slots 22, 22 arranged at an intervalfrom each other in the X-axial direction, each fixed piece 14 a isdisposed such that the first upright portion 28 b is located on theinner corner side for both slots 22 to approach each other, and a secondupright portion 28 c is located on the outer corner side. Each firstupright portion 28 b and each second upright portion 28 c extend along acenter line L of the slot 22 from the bottom 28 a at right angles to thebottom portion. The second upright portion 28 c terminates approximatelyat an intermediate height position of the slot 22, as shown in FIG. 4.On the other hand, the first upright portion 28 b extends over theintermediate height position of the slot 22 and terminates at an upperend face subsequently coinciding with the upper face 12 b.

Both outer faces 30 b and 30 c, respectively, of the first uprightportion 28 b and the second upright portion 28 c are upright planesparallel to the center line L of the slot 22. Also, the inner face 32 cof the second upright portion 28 c, confronting the first uprightportion 28 b, is an upright plane parallel to the center line L of theslot 22. On the other hand, the inner face 32 b of the first uprightportion 28 b, facing the second upright portion 28 c, is a straightinclined guide face having a depression angle θ with respect to thecenter line L of the slot 22 from the bottom face 12 a of the basemember 12 toward the upper face 12 b. This angle θ is preferably withina range of several degrees to about 30°, as mentioned later.

Substantially at the intermediate height position of the straightinclined face 32 b, as shown in FIGS. 4 and 5, a shallow groove 34 forreduction of friction with the movable piece 14 b as mentioned later isformed along the Y-axial direction. Also on the outer face 30 b of thefirst upright portion 28 b of each fixed piece 14 a, a recess 36 isformed on the outer face 30 b, and on the peripheral wall in one cornerportion corresponding to the slot 22, a projection 38 (see FIG. 4)engageable with the recess 36 is formed.

The fixed piece 14 a of each contact 14 is, for example, pushed from thefront end of the first upright portion 28 b into the corresponding slot22 from the bottom face 12 a of the base member 12 so as to avoid theprojection 38, with the tip of the first upright portion 28 b warpedslightly toward the second upright portion 28 c, thereby engaging theprojection 38 and the recess 36. By the engaging mechanism having thisprojection 38 and the recess 36, each fixed piece 14 a is engaged at apredetermined position of the corresponding slot 22.

The movable piece 14 b has an inclined face 40 slidably abutting thestraight inclined guide face 32 b between the first upright portion 28 band the second upright portion 28 c, and an arc-shaped fitting curvedface 42 formed on the side opposite to the inclined face. The fittingcurved face 42 of each movable piece 14 b disposed within each slot 22sandwiches the elastic member 16 in a partially compressed state incooperation with the top of the second upright portion 28 c of eachfixed piece 14 a disposed within each slot, as shown in FIG. 4, and thefitting portion 44 formed at the other corner portion of the slot 22. Bythe elastic biasing force of the sandwiched elastic member 16, themovable piece 14 b receives spring force upward of the inclined face,with the inclined face 40 of the movable piece 14 b along the straightinclined face 32 b of the fixed piece 14 a, such that the projectedportion 46 formed on the top of the movable piece projects from theupper face 12 b of the base member 12.

The movable piece 14 b can be assembled into the fixed piece 14 a bypushing the bottom portion on the side opposite to the projected portion46, for example, with the elastic member 16 sandwiched between thefitting portion 44 formed on the peripheral wall of the slot 22 of thebase member 12 and the second upright portion 28 c of the fixed piece 14a engaged with the base member 12, such that the movable piece 14 breceives the elastic member 16 on the fitting curved face 42. Thus, whenthe contact 14 is assembled into each slot 22, the wiring base plate 48is disposed on the bottom face 12 a of the base member 12, as shown inFIG. 4. On one face of the wiring base plate 48, a plurality of wiringportions 48 a to be electrically connected to the tester 50 are formed,and the wiring base plate 48 is fixed at the base member 12 by means ofbolts (not shown), so that each wiring portion 48 a contacts theunderside of the bottom portion 28 a of the fixed piece 14 a to whicheach wiring portion 48 a corresponds. This completes assembling of theelectrical connection apparatus.

As shown in FIG. 1, in the assembled electrical connecting apparatus 10,the semiconductor IC 20 is dropped into the opening portion 18 a of thecover member 18. As shown in FIG. 6, when the lead 20 a of thesemiconductor IC 20 abuts the projected portion 46 in the movable piece14 b of the contact 14 corresponding thereto, external force F isapplied to the semiconductor IC 20 in this state of abutment, and thisexternal force F, surpassing the elastic biasing force of the elasticmember 16, causes the projected portion 46 of the movable piece 14 b tobe pushed down as a whole in the plate thickness direction (Z-axialdirection) of the base member 12 toward the position indicated by thesolid line from the position indicated by the broken line in thedrawing. At this time, the movable piece 14 b, as it slides on thestraight inclined guide face 32 b of the fixed piece 14 a on which theinclined face 40 abuts, slightly displaces in the X-axial directionaccording to the angle of inclination θ of the inclined guide face dueto the guiding action of the straight inclined guide face. Because ofthe X-axial displacement following the displacement in the Z-axialdirection of the movable piece 14 b, the projected portion 46 of themovable piece 14 b scrapes away the oxide film of the contact face ofthe lead 20 a of the semiconductor IC 20, thereby surely preventing theintervention of the oxide film for contact with the lead 20 a.

Also, the contact between the lead 20 a and the projected portion 46 ismade under the elastic biasing force of the elastic member 16, and partof the elastic biasing force acts as contact pressure between theinclined face 40 of the movable piece 14 b and the straight inclinedguide face 32 b of the fixed piece 14 a, so that each lead 20 a isconnected to the wiring portion 48 a connected to the fixed piecethrough the movable piece 14 b of the corresponding contact 14. As aresult, each lead 20 a of the semiconductor IC20 is surely connected tothe tester 50.

Moreover, since the fixed piece 14 a of each contact 14 is surely fixedwithin the corresponding slot 22 by the engaging mechanisms 36, 38respectively, even if the movable piece 14 b slides on the straightinclined guide face 32 b of the fixed piece 14 a, movement of the fixedpiece 14 a by the elastic biasing force of the elastic member 16 issurely prevented. Consequently, abrasion of the fixed piece 14 a and thewiring portion 48 a of the wiring base plate 48 by their relative motioncan be prevented, so that lowering in durability due to the abrasion canbe prevented.

Thus, according to the electrical connecting apparatus 10 of the presentinvention, since abrasion of the fixed piece 14 a and the wiring portion48 a of the wiring base plate 48 due to their relative motion can beprevented, thereby improving the durability.

Also, when the front end of the projected portion 46 of the movablepiece 14 b is projected from inside the slot 22 at the contact positionwith the lead 20 a of the semiconductor IC 20, surer electricalconnection between the lead 20 a, i.e., the electrode of thesemiconductor IC 20, which is a device under test, and the contact 14 isenabled.

Various engaging mechanisms can be adopted for coupling the fixed piece14 a and the base member 12. By use of the engaging mechanisms 36, 38 asmentioned above, however, the fixed piece 14 a can be surely and easilycoupled with the base member 12 fixedly.

As regards sliding of the movable piece 14 b along the straight inclinedguide face 32 b of the fixed piece 14 a, the rate of the displacementamount of the Z-axial component and the displacement amount of theX-axial component of the movable piece 14 b varies by the inclinationangle θ. The nearer the value of θ to zero, the rate of the former tothe latter becomes greater. As the amount of displacement of the X-axialcomponent increases, it is feared that, when the electrode 20 a of thedevice under test 20 is pressed against the movable piece 14 b of thecorresponding contact 14, the projected portion 46 of the movable piecemight be extruded from the corresponding electrode 20 a. In aminiaturized semiconductor device provided with a smaller electrode,too, it is preferable to determine the inclination angle θ within arange of several degrees to about 30° as mentioned above for surelypreventing the movable piece 14 b from deviating from the electrode 20 aof the projected portion 46 and for ensuring the action to remove theoxide film. Thus, the present invention can be applied to an electricaltest of an IC semiconductor wafer with IC circuits collectively formed.

Also, while the straight inclined guide face 32 b can be an arc-likecurved face, it is preferable to constitute it a straight guide face asmentioned above, for accuracy in machining of the guide face and forenabling more accurate control of the displacement amount of the X-axialcomponent to the displacement amount of the Z-axial component of themovable piece 14 b.

By providing the fixed piece 14 a with the first and second uprightportions 28 b, 28 c, forming the guide face 32 b of the movable piece 14b in relation to the first upright portion 28 b, and disposing theelastic member 16 in relation to both upright portions 28 b, 28 c,compact contacts 14 having a relatively simple constitution and theelectrical connecting apparatus 10 having the contacts can bematerialized.

By disposing a single elastic member 16 at each row of the slots 22, soas to cross the row of the slots, elastic biasing force favorable foraction of plural contacts can be given so that a favorable electricalconnection can be obtained by the elastic biasing force of the singleelastic member 16. Consequently, there is no need for two elastic bodiesin each row of slots as heretofore, thereby simplifying theconstitution.

FIGS. 7 and 8 show examples of using a Kelvin connector contact 114 asthe contact 14. The Kelvin connector contact is, as has been well known,formed from a laminated structure with an insulator interposed between apair of conductive plates spaced apart from each other. Consequently,also in the Kelvin connector contact 114 according to the presentinvention, its fixed piece and movable piece are composed of a pair ofconductive plates 114 a and 114 b joined to each other with aninsulating plate 114 c interposed therebetween.

Each conductive plate 114 a for the fixed piece has a first uprightportion 128 b including a recess 136 and a straight inclined guide face132 b of an engaging mechanism such as one mentioned above, a secondupright portion 128 c shorter than the upright portion 128 b, and abottom portion 128 a for coupling both the upright portions. Also, eachconductive plate 114 b for the movable piece has an inclined face 140opposite to the straight inclined guide face 132 b, a fitting curvedface 142 for receiving the elastic member 16, and a projected portion146.

Both conductive plate 114 a for the fixed piece are joined through theinsulating plate 114 c to be interposed therebetween so as to preventboth conductive plates from short-circuiting. In this insulating plate114 c, the recess 136 a which fits the recess 136 of the conductiveplate 114 a and a fitting curved face 142 a receiving the elastic member16 are formed. Both conductive plates 114 b for the movable piece areassembled into the slots 22 of the base member 12 like theabove-mentioned one (not shown) on both sides of the insulating plate114 c in a state that mutual short-circuiting is prevented by theinsulating plate, that the elastic member 16 is received in the fittingcurved face 142, and that each inclined face 140 is brought into contactwith the corresponding straight inclined guide face 132 b.

Also, as shown in FIG. 8, a pair of wiring portions 48 a are formed inthe wiring base plate 48 to correspond to each conductive plate 114 a ofthe fixed piece of the contact 114, and each wiring portion 48 a isconnected to the corresponding conductive plate 114 a.

According to this Kelvin connector contact 114, as is well knownheretofore, two wiring portions 48 a can be drawn out from one lead 20a, thereby enabling the Kelvin connection in which a voltage applyingroute and a voltage detecting route are separated, and even a lowresistance value of the device under test 20 can be measured at highaccuracy by reducing influence by contact resistance of the contacts.

Also, according to the Kelvin connector contact 114 in the presentinvention, likewise in the case of the contact 14, each conductive plate114 a of the fixed piece is fixedly held by the base member 12, so thateach conductive plate 114 a does not slide on the wiring portion 48 a ateach testing of the semiconductor IC 20, so that no abrasion by slidingis caused, thereby improving the durability.

INDUSTRIAL APPLICABILITY

The present invention is not limited to the above embodiments, but canbe varied without departing from its purport.

1. An electrical connecting apparatus for connecting electrodes of adevice under test to an electric circuit of a tester, comprising: anelectrically insulating plate-like base member for receiving said deviceunder test and having a plurality of slots penetrating through the basemember; contacts disposed within said slots so as to contact saidelectrodes of said device under test on said base member and forconnecting said electrodes to the electric circuit of said tester; andan elastic member; wherein each contact includes: a fixed piece mountedon said base member within said slot for connection with said electriccircuit; and a movable piece disposed within said slot and electricallyconnected to said fixed piece, said fixed piece having a guide facearranged for guiding said movable piece toward a contact position forpermitting said movable piece and said electrode to contact; and whereinsaid movable piece is supported by said elastic member and slidablypositioned on said guide face so as to receive elastic biasing forcetoward said contact position.
 2. An electrical connecting apparatusaccording to claim 1, wherein a wiring base plate is fixed on one faceof said base member, wherein said base member receives said device undertest on the other face thereof; wherein said wiring base plate has awiring portion to be connected to said electric circuit of said testerand for said fixed piece to contact, and through said wiring portion,said fixed piece is electrically connected to said electric circuit. 3.An electrically connecting apparatus according to claim 2, wherein saidmovable piece has a projected portion capable of projecting from withinsaid slot beyond the other face of said base member; and wherein the tipof said projected portion projecting from within said slot at thecontact position comes in contact with said electrode.
 4. Anelectrically connecting apparatus according to claim 1, wherein saidfixed piece is engaged with the peripheral wall of said slot of saidbase member by an engaging mechanism.
 5. An electrically connectingapparatus according to claim 4, wherein said engaging mechanism has aprojection formed in said peripheral wall of said slot, and a recessformed in said fixed piece for engagement with said projection.
 6. Anelectrically connecting apparatus according to claim 1, wherein saidguide face is formed angularly with respect to a center line penetratingboth end openings of said slot, so as to impart both lateral andvertical movement relative to the centerline when said movable pieceslides along said guide face.
 7. An electrical connecting apparatusaccording to claim 6, wherein said guide face is a straight guide faceextending angularly with respect to said center line of said slot.
 8. Anelectrical connecting apparatus according to claim 7, wherein said fixedpiece has a bottom portion disposed along one face of said base memberwithin said slot and along the longitudinal direction of said slot; afirst upright portion rising from one corner portion of said bottomportion along the longitudinal direction of said slot toward the otherface of said base member along the wall face of said slot; and a secondupright portion rising from the other corner portion of said bottomportion along said first upright portion at an interval to said firstupright portion; wherein said guide face is formed on the face of saidfirst upright portion confronting said second upright portion; andwherein said movable piece receives elastic biasing force of saidelastic member between both said upright portions so as to come incontact with said guide face.
 9. An electrically connecting apparatusaccording to claim 1, wherein said plural slots are aligned in theirwidth direction, wherein in each of said contacts said movable piece andfixed piece are aligned within each of said slots, and wherein saidsingle elastic member is disposed across said aligned slots in the widthdirection of said slots so as to apply said elastic biasing force toeach movable piece within said plural aligned slots.
 10. An electricalconnecting apparatus according to claim 1, wherein said contact is aKelvin connector contact made of a laminated structure including a pairof conductive layers and an electrically insulating layer interposedbetween said conductive layers.
 11. A method of interfacing asemiconductor device-under-test (DUT) to an electric circuit of a testerdevice, the method comprising the steps of: providing a contact forestablishing a temporary electrical connection between a lead of the DUTand the electric circuit of the tester device, the contact comprising afixed part and a movable part; establishing electrical contact betweenthe fixed part and the electric circuit of the tester device; mountingthe movable part for sliding engagement along a guide surface of thefixed part, said sliding engagement providing continuous electricalcontact between the fixed part and moving part, while permittingmovement of the movable part relative to the fixed part; biasing themovable part toward a standby position; moving a lead of the DUT intomechanical and electrical contact with the movable part so that the leaddisplaces the movable part, characterized by a sliding action of themovable part along the guide surface of the fixed part, from the standbyposition into a testing position; wherein the movable part is displacedlaterally in moving from the standby position to the testing position soas to scrape a surface of the DUT lead where the movable part contactsthe DUT lead, thereby improving electrical conductivity with the leadwithout displacing the fixed part that provides electrical contact withthe electric circuit of the tester device.
 12. A method according toclaim 11 wherein said biasing step includes providing an elastic memberin contact with the movable part.
 13. A method according to claim 12wherein both the fixed part and the movable part are formed of metal.14. A method according to claim 12 wherein the fixed part is mounted ina predetermined position in both mechanical and electrical contact withthe electric circuit of the tester device, so that movement of themovable part does not wear or abrade the electrical circuit contacts.15. A method according to claim 11 including: providing a plurality ofcontacts for establishing corresponding temporary electrical connectionsbetween respective leads of the DUT and the electric circuit of thetester device, each contact comprising a fixed part and a movable part;and wherein said biasing of the moveable parts comprises providing asingle elastic member and disposing the elastic member across all of thecontacts so as to bias the movable parts of all of the contacts.
 16. Amethod according to claim 11 including: providing an elastic member forbiasing the movable part toward the standby position, the elastic memberhaving a generally round cross-section; and forming a recess in themovable part sized and arranged for receiving the elastic member foroperatively biasing the position of the movable member.
 17. A methodaccording to claim 11 including: providing a rigid, substantially planarbase member formed of an insulating material; forming a slot extendingthrough the base member between a top surface and a bottom surface; andpositioning the contact in the slot with the movable part extending outof the slot for contacting the DUT.
 18. A method according to claim 17including: arranging the elastic member in the slot for retaining themovable part substantially within the slot.
 19. A method according toclaim 18 including arranging the fixed part so as to retain the movablepart substantially within the slot.
 20. A method according to claim 19including removably engaging the fixed part within the rigid base memberso as to retain the movable part substantially within the slot.